1. Field of the Invention
The present invention relates to a mount assembly for a vibrating component. The invention includes a supported mount supported on a machine part, a supporting mount supported via a spring element on the supported mount, and an inertial mass. The inertial mass is reciprocable by a drive in a direction parallel to the direction of the vibrations introduced during operation of the vibrating component. The inertial mass is spring-mounted and is controllably movable in a direction opposite from the exciting vibration, and is joined to the supported mount by a spring. The mount assembly is connected to a control system for ensuring that the inertial mass vibrates opposite from the exciting vibration, to thereby reduce the vibrations of the vibrating component.
2. Description of the Prior Art
A mount assembly is shown in German Patent 34 33 255. This patent describes a vibration-damping mount whose damping device and compensation membrane are actively influenced. An actuator is acted upon by a control unit including a computer, in order to achieve compensation for pressure changes in the damper fluid caused by interference vibrations of the vibrating body. The computer receives a reference input signal detected with a signal transducer. The reference input signal can be, for example, the engine speed as well as at least one further signal characterizing the state of the vibrating body. The computer is fully programmable as a function of the reference input variable. In and of itself, a control system of this kind creates an ability to compensate for all vibration body-related interference vibrations that occur. However, completely new programming for the computer is needed for each application, which is undesirable and laborious, especially when used in vehicles with different bodywork and equipment. It is not possible in the device described in this patent to detect airborne sound components. However, the spectrum of all possible interference vibrations--and those that actually occur--as a result of real-world driving is insufficiently covered by this device. In addition, utilization of control data, calculated at great effort and stored in the computer, is advisable only so long as there are no secondary changes in the system. For example, a change in the weight of the supported masses and/or an age-related change in the elasticity of the rubber components within the rubber mount cannot be compensated for.
German Patent No. 41 04 168 shows a hydraulically damped rubber mount that is used to support a mechanical accessory, which movies in vibratory fashion on a support, in which a fluid-filled working space is associated with an actuator provided with an electromagnetic drive. The drive has a triggering system that is joined in a signal-carrying manner, to a first signal transducer on the mechanical accessory. The triggering system includes a signal generator, a characteristics diagram control system, and a power amplifier as the output stage. The actuator is provided with an electromagnetic drive with which, when vibrations are introduced into the upper part of the rubber mount, pressure changes excited in the fluid-filled working space can be compensated for in such a way that any transfer to the machine element is prevented. The hydraulic damping mount, including its control system, is used only in connection with vibrations that arise in the engine. Vibrations arising in other components are not detected. The complex configuration of the mount and the extensive circuit mechanism needed to control interference vibrations in this devices tend to raise costs of such a device.
German Published Application No. 41 23 254 shows a control system for active mount elements, in particular for mount elements used to mount engines in motor vehicles. This publication describes a control system for active mount elements, individual or arranged in groups, and in particular active mount elements for mounting engines in motor vehicles. Sensors in this device detect interference vibrations and vehicle-specific general parameters. These parameters may be, for example, the engine speed, a selected gear, throttle valve position, and the like. This control system uses a control circuit to process the signals from the sensor and one actuator each to act on the mount element or elements as a function of the output signal of the control circuit. The control circuit also refers back to a vehicle-specific characteristics diagram stored in memory. This characteristics diagram is created by trial and error, and from it--in conjunction with the variables detected by sensor--are generated signals that the control circuit helps to process. This characteristics diagram also accounts for airborne transmission parameters detectable by sensors, and for other variables that can be measured only with great effort. The complex circuit arrangement is disadvantageous; too much data is detected, so that a larger memory capacity must be present. This requirement results in increased costs. Details of the mount assembly of this device will not be discussed specifically.